Zener Diode Question

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Kcz5o
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Zener Diode Question

Post by Kcz5o »

I purchased a Ceriatone Son of Yeti kit. The only information that came with the kit was a jpeg layout that is somewhat difficult to see. The jpeg show two blue and two red zener diodes. The packing list show that 2 are 1N4747a diodes (20 watt I think) and two are 1N4739a (9 watt). Does anyone know which are indicated by the blue and which are indicated by the red? Might have bit off more that I can chew. Didn't even give the specs for the transformers. I found what looks like a similar one on their website for a different amp to identify the PT leads. I've attached the layout jpeg and a amp chassis jpeg. Thanks much!
SonoFYetiLayout-1Dec2019.jpg
chassis.jpg
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Kcz5o
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Re: Zener Diode Question

Post by Kcz5o »

The more I think about it it wouldn't matter correct? If I switched them around it would reverse the switch and if I happened to put the two different diodes together on each side it would just sound the same on both sides. Sound right? Thanks
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TriodeLuvr
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Re: Zener Diode Question

Post by TriodeLuvr »

The 4747A is a 20V, 1W Zener. The 4739A is 9.1V, 1W. Sorry, can't tell you which location they should be in without seeing the schematic.

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Re: Zener Diode Question

Post by JMPGuitars »

Kcz5o wrote:
Thu 03/11/21 10:26 pm
The more I think about it it wouldn't matter correct? If I switched them around it would reverse the switch and if I happened to put the two different diodes together on each side it would just sound the same on both sides. Sound right? Thanks
Correct. If you want to match the build, I'm guessing the red ones are the 9.1V, as those are usually red diodes. Just mind the orientation of the stripes, and you should be fine.

Thanks,
Josh
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Kcz5o
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Re: Zener Diode Question

Post by Kcz5o »

Thanks, I didn't get a schematic and the layout isn't really clear either.
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geoff 1965
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Re: Zener Diode Question

Post by geoff 1965 »

this is'nt a ceriatone schematic but it's obviously someone's take of the amp,anyway it show's the "era" switch in question and the orientation of the diodes.
Yeti, Son of.gif
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Re: Zener Diode Question

Post by TriodeLuvr »

What do the diodes look like that came in the kit? The datasheets say both types are glass. The photo you posted shows that too, with one being clear glass that allows viewing the red inner structure, and the other being gray/black.

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Re: Zener Diode Question

Post by katopan »

Looking at the layout pic, the two chains are connected at one end and go to the switch at the other end. For the leads to the switch not to cross over, it depends which value you want in circuit for which switch position. ie. It doesn't really matter and if it turns out backwards, swap the switch wires over.

Like has already been suggested, it would seem that the red ones would correspond to the glass type and the blue would correspond to the silver ones.
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Kcz5o
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Re: Zener Diode Question

Post by Kcz5o »

I am starting to get this together and have another question. I hope its alright to post on this diode post rather than start a new topic. In the diagram from Ceriatone (shown in first post) it shows that the input shielded wire is grounded at the input, and then the ground wire at the other end of the cable is hooked to a 1meg resister going to pin 2 of the 12ax7. Am I understanding the diagram correctly. Thanks again for all the help.
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Re: Zener Diode Question

Post by Bieworm »

Sorry, but I don't understand why members of this site even look at other schematics. Josh has done a lot of efforts to create clear layouts of a lot of 18W variants. In the download section of this site you'll find a lot of schematics and layouts that are more than clear ...
The 1M resistor is to be soldered across the cliff jack input, and not at pin 2 of the input triode. There is a grid stopper resistor that has to be soldered right there at pin 2, but that's a 10k, or a 22k on the ceriatone. You put a terminal near V1 and solder the grid stopper from the terminal to pin 2. From the terminal you run a shielded wire to the input jack's hot tip, grounding the shield only at the input side. You must avoid the other end of the shield touching anything else, so it's best to seal it off with heatshrink tubing.
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geoff 1965
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Re: Zener Diode Question

Post by geoff 1965 »

i have to disagree with that,this is'nt your typical 18 watter,the configuration he described is correct to the layout and schematic,this ceriatone is very high gain with some trickery so maybe it needs to be like that?
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Kcz5o
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Re: Zener Diode Question

Post by Kcz5o »

Thanks much. I will give it a try as it is layed out and if there are issues try the above suggestion.
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Re: Zener Diode Question

Post by TriodeLuvr »

Kcz5o wrote:
Fri 03/19/21 11:37 am
In the diagram from Ceriatone (shown in first post) it shows that the input shielded wire is grounded at the input, and then the ground wire at the other end of the cable is hooked to a 1meg resister going to pin 2 of the 12ax7. Am I understanding the diagram correctly. Thanks again for all the help.
Yes, that's how it's being done. The cable shield is being used to ground the 1M resistor. The shield is only grounded at the input jack (using the ground wire connected from there to the turret board).

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Re: Zener Diode Question

Post by TriodeLuvr »

Bieworm, the layout you posted shows wires on pins 1 and 6 of V1 that are both labeled "shielded wire." However, there's no ground connection at either wire. Is the label wrong?

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Re: Zener Diode Question

Post by Bieworm »

TriodeLuvr wrote:
Sun 03/21/21 12:18 pm
Bieworm, the layout you posted shows wires on pins 1 and 6 of V1 that are both labeled "shielded wire." However, there's no ground connection at either wire. Is the label wrong?

Jack
It's a layout from Josh. I don't think he draws the grounded side of shielded wires. But it's common practice the shielded wire is grounded at one end
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